Are you a tank or DPS, from what I can see you are a tank....anyways, if you want to do as much DPS as Possible I recommend using the 0/17/54 Unholy Spec which you can view here..

Make sure you copy the same glyphs that are there, as they are basically all you will need, also I will include some pointers too

1. You MUST always keep your diseases up at all times, never let them 'Run Off' this does not really apply to Random Heroics or Dungeons, but if you can Great! and use Pestilence! you can apply your main diseases to a target by using Icy Touch (Rank 5) and Plague Strike (Rank 6)

2. Remember to ALWAYS remain in Blood Presence when DPS'ing, yes you are specced for Unholy, but that does not mean you automatically use Unholy Presence, the only thing that is good for is increasing your run speed (Usefull in the Professor Putricide Encounter but anyway blood increases damage done by 15%, That's a lot

3. Always gem +20 Strength Bold Cardinal Ruby unless you are low on Hit Rating and/or Expertise Rating, The hit cap for Unholy Death Knights in PvE Raids is 8% and the Expertise cap is 26, try to aim for those caps if you can, and gemming +20 Exp with a current un-gemmed Exp rating of 19 is going to take a lot of gems, so only use 2 or 3 if you have enough slots, and remember that for every 1 Strength Point = 2 Attack Power Points, so NEVER gem Attack power, It's okay to Enchant it, but just please don't gem it

4. Make sure you have all the enchants needed, using wow-heroes.com you can determine which enchants to use depending on what is at the top of the list, but you still need a basic knowledge of what stats you need, to determine exactly which enchant is best for you

5. Always use Bone Shield Before going into an Encounter as it will increase your total damage by 2%, lasts 5 minutes so you don't have to worry about it much, also, always make sure you eat from a Fish Feast before clicking Yes on the ready check and that you have used one of your Flask of Endless Rage if you have any on you, if you don't, or never knew they existed I really recommend you get some before your next raid, this buff last 1 hour and the effect even stays with you after death. (Do not use for Random Heroics, It would be a waste....)

6. Rotation, now I know what you are thinking, and yes, rotation is annoying, but it does increase your damage output exponentially, once you get the hand of keeping your diseases up the rotation will become rather easy, first and foremost always apply your diseases and remember to use Scourge Strike every time it is available, but do not wait for it not pushing buttons, there has to be absolutely no downtime while DPS'ing as a Death Knight, so anyway, here is the easiest rotation for this Unholy Spec:

Simple, don't you think? Well, kinda, there is no actual rotation for a death knight so basically that is a start off rotation, so you have you diseases up, Icy Touch and Plague Strike, Blood Strike twice then Death Coil Twice, if you have enough Runic Power, then pop Horn of Winter, it will generate 10 Runic Power, so now you ask, what do I do?! Well, you need to keep an eye on your diseases and try not to push Icy Touch or Plague Strike again until your diseases are about to fall off, the best way to get better at this is to practise on a dummy, and try to get your diseases to get as close to 'Dropping Off' as possible before you refresh, this will allow more time for you to DPS..

Now all you need to do after you start of with that rotation is SS, BS and DC, until you need to refresh your diseases again, you will not need to use HoW again until it runs off, also when you notice your trinket procs are at max, pop your Summon Gargoyle to lay some extra DPS on the Boss, the reason for letting your trinkets 'proc' is because the Gargoyle's damage output is modified by your own Attack Power

Please also to remember about your Blood Tap and Empower Rune Weapon if you find yourself not able to use any spells while your diseases are up

5. Don't forget, you are babysitting a minion now with this spec, make sure to summon him before going into battle, and keep him under control in Defensive Mode

6. Have Fun, Death Knights are a really fun class, but can be especially hard to play at times

Okay well that took an hour or 2 to write so I hope it helps, and others too, if you still have any questions, just reply and I can see if I can help